In general, as a display device, a liquid crystal display device is known. The liquid crystal display device uses various conductive layers. As the conductive layers, lines extending in a display area for displaying an image are present. The reflectances of such lines can be reduced if they are blacked. As a result, they can become visibly unrecognizable.
Also, as the above conductive layers, lines located outside of a liquid crystal display panel are present. Such lines are easily damaged by water contained in the outside air, as compared with lines located in the liquid crystal display panel. Thus, there is a case where it is demanded that lines having high resistance to corrosion be formed.
Furthermore, as the above conductive layers, lines having a stacked structure formed of a plurality of kinds of materials are present. In such lines, when electrical conduction is carried out in a high temperature and humidity environment, electrolytic corrosion easily occurs, and easily causes a failure of the lines such as breaking of them.